Transferring to new pc

I have a single pc license that is due 31st March 2009.I wish to install it on my new pc (offline atm). I have the original install CD. Old pc is current with ver 2845.
Any specific procedures that i need to follow with this ,I imagine there might be a conflict with existing username/password if I have to reactivate it?
I looked in faq ,sorry but couldnt find any details.